Describe the work
Share what you need, whether you have a detailed plan or are still exploring the options.
What an AFDD does
Electrical fires can cause serious damage to a business, and arc fault protection is one way to reduce the risk. An arc fault detection device (AFDD) monitors a circuit for the electrical signature of dangerous arcing, caused by damaged cables, loose connections or worn equipment, and switches the circuit off before it can start a fire.
Ordinary circuit breakers react to overloads and short circuits, and RCDs react to current leaking to earth. Neither is designed to detect a series arc in a damaged cable behind a wall or in a loose terminal, which is the gap an AFDD fills. In offices, shops, restaurants and other busy workplaces, where wiring runs through ceilings and partitions and equipment runs for long hours, that extra layer of protection can be valuable.
What the Wiring Regulations say
AFDDs to BS EN 62606 are covered by regulation 421.1.7 of BS 7671:2018+A4:2026, the current IET Wiring Regulations. They are required on single-phase AC final circuits supplying socket-outlets rated up to 32 A in higher-risk residential buildings, houses in multiple occupation (HMOs), purpose-built student accommodation and care homes. For other premises, including most offices and shops, BS 7671 recommends them. The rule is not retrospective. Businesses also have a general duty under the Electricity at Work Regulations 1989 to keep their electrical systems safe.
How installation works
The qualified electricians you compare through Kilowatts UK start by surveying the distribution board and the circuits that would benefit most. In a modern board, existing circuit breakers or RCBOs can often be replaced with combined AFDD/RCBO devices from the same manufacturer, so the board stays within its type-testing. Older boards may not accept them, in which case replacing the board is the better route. Work can be planned outside trading hours to keep disruption down.
Many businesses fit AFDDs at the same time as distribution board upgrades, RCD protection or after commercial electrical inspections, which can reduce cost and downtime.
Certificates and maintenance
Adding AFDDs to existing circuits is normally recorded on a Minor Electrical Installation Works Certificate (MEIWC); a new board or new circuits should come with an Electrical Installation Certificate (EIC). Many AFDDs have a test button or a self-test function; follow the manufacturer's instructions. Electrical Safety First recommends periodic inspection of a business installation at least every five years, with shorter intervals where the inspector thinks it necessary. If you are planning solar as well, the commercial solar comparison tool lets you compare installers for both projects. Submit your project details, compare quotes from local electricians, or call Kilowatts UK free on 0800 009 6058.